Temporary dental cements are routinely used for the temporary cementation of crowns and other prostheses to dentin and enamel surfaces. Many of the commonly used temporary dental cements contain zinc-oxide eugenol (ZOE) due to its short setting time and good short-term marginal sealing effects. After a tooth restoration procedure has been performed using ZOE-containing cements, instruments and work-pieces must be cleaned in order to remove these cements. These ZOE-containing temporary cements must also be thoroughly removed from collagen-containing surfaces, such as dentin, enamel and bone, during tooth restorations as well as from temporary crowns and other prostheses before applying a resin-based permanent cement. Permanent prostheses are often cemented with acrylate resin-based compositions. The bonding ability of these permanent resin cements is severely hindered by the presence of eugenol in the temporary cement, undermining the success of the permanent restorations. This is due to the fact that eugenol is a problematic inhibitor of polymerization of composite restorative polymeric materials in permanent cements.
Current methods for removing temporary cement from instruments, work-pieces, prostheses, and collagen-containing surfaces are inadequate, as gross amounts of cement remain on the surface. This may result in unintended contamination of the residual cement with other chemicals when the instrument is subsequently used for another procedure. In addition, current ZOE-removing compositions are toxic, rendering them incapable of internal use in the oral cavity and requiring special disposal procedures. For example, currently available temporary cement removers, such as Advanced Formula Temporary Cement Remover (L&R Manufacturing Company) and VK-6 Temporary Cement Remover (Heraeus Kulzer North America), contain harsh inorganic bases, and therefore, can only be used outside the oral cavity. Currently, there is no commercially available temporary cement removal that is safe for use inside the oral cavity.
Accordingly, there is a need for compositions that effectively and efficiently remove ZOE-based temporary cements from a variety of surfaces. In addition, these compositions must be non-toxic so that they can be used on collagen-containing surfaces within the oral cavity and so as not to require special disposal procedures.
During tooth restoration procedures, temporary cements are removed and replaced with permanent cements, such as cements containing acrylate resins. Therefore, efforts have been made to not only thoroughly remove the temporary cements from the tooth, but to increase the adhesion of the acrylate resin permanent cements to collagen-containing surfaces such as the dentin of the tooth. The acrylate resin-dentin bond between permanent cements and collagen-containing surfaces can be strengthened with the use of desensitizing agents. Accordingly, there is a need for a single composition that effectively and efficiently removes ZOE-based temporary cements from a variety of surfaces as well as strengthens the resin-dentin bond between permanent cements and collagen-containing surfaces.
Treatment of pulp disease or apical periodontitis commonly involves the insertion of a gutta-percha cone into the root canal, followed by the sealing of the canal with a dental cement. Dental gutta-percha cones and sealants are typically composed of ZOE. However, the use of ZOE does not always provide a long-lasting seal, resulting in possible bacterial infiltration and infection. In such cases, it is necessary to re-treat the canal. Current methods of re-treating include removal of the gutta-percha cone and cement sealer via mechanical instrumentation with a reamer or file Because the gutta-percha cone and sealer materials are tough, using a reamer or file is often time consuming and inadequate. A practitioner may often use toxic chemicals, such as chloroform and xylene, to aid in the removal of the root canal materials; however, these chemicals must be used in very small quantities as they are known carcinogens. Accordingly, there is a need for a non-toxic composition for removing root canal filling materials during endodontic re-treatment cases.